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/*
* This file is part of the coreboot project.
*
* Copyright 2015 Google Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc.
*/
#ifndef _REGION_H_
#define _REGION_H_
#include <stdint.h>
#include <stddef.h>
/*
* Region support.
*
* Regions are intended to abstract away the access mechanisms for blocks of
* data. This could be SPI, eMMC, or a memory region as the backing store.
* They are accessed through a region_device. Subregions can be made by
* chaining together multiple region_devices.
*/
struct region_device;
/*
* Returns NULL on error otherwise a buffer is returned with the conents of
* the requested data at offset of size.
*/
void *rdev_mmap(const struct region_device *rd, size_t offset, size_t size);
/* Unmap a previously mapped area. Returns 0 on success, < 0 on error. */
int rdev_munmap(const struct region_device *rd, void *mapping);
/*
* Returns < 0 on error otherwise returns size of data read at provided
* offset filling in the buffer passed.
*/
ssize_t rdev_readat(const struct region_device *rd, void *b, size_t offset,
size_t size);
/****************************************
* Implementation of a region device *
****************************************/
/*
* Create a child region of the parent provided the sub-region is within
* the parent's region. Returns < 0 on error otherwise 0 on success. Note
* that the child device only calls through the parent's operations.
*/
int rdev_chain(struct region_device *child, const struct region_device *parent,
size_t offset, size_t size);
/* A region_device operations. */
struct region_device_ops {
void *(*mmap)(const struct region_device *, size_t, size_t);
int (*munmap)(const struct region_device *, void *);
ssize_t (*readat)(const struct region_device *, void *, size_t, size_t);
};
struct region {
size_t offset;
size_t size;
};
struct region_device {
const struct region_device *root;
const struct region_device_ops *ops;
struct region region;
};
#define REGION_DEV_INIT(ops_, offset_, size_) \
{ \
.root = NULL, \
.ops = (ops_), \
.region = { \
.offset = (offset_), \
.size = (size_), \
}, \
}
static inline size_t region_sz(const struct region *r)
{
return r->size;
}
struct mem_region_device {
char *base;
struct region_device rdev;
};
/* Iniitalize at runtime a mem_region_device. This would be used when
* the base and size are dynamic or can't be known during linking. */
void mem_region_device_init(struct mem_region_device *mdev, void *base,
size_t size);
extern const struct region_device_ops mem_rdev_ops;
/* Statically initialize mem_region_device. */
#define MEM_REGION_DEV_INIT(base_, size_) \
{ \
.base = (void *)(base_), \
.rdev = REGION_DEV_INIT(&mem_rdev_ops, 0, (size_)), \
}
#endif /* _REGION_H_ */
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